RU2697602C2 - Device for suction of steam-air mixture from condenser of steam turbine - Google Patents

Abstract

FIELD: heat power industry.SUBSTANCE: steam-air mixture blow-off device (SAM) from steam turbine (ST) of steam turbine plant (STP) consists of water jet ejector with pressure nozzle connected to water supply line from circulation system of said ST cooling. Device is additionally equipped in parallel by steam-jet ejector (SJE) connected by suction STP, pressure nozzle of which is connected to line of one of intermediate takeoffs of steam of said ST, its exhaust branch pipe – to inlet of surface cooler connected along cooling side to the section line of condensate path between regenerative heaters of low pressure of said STS.EFFECT: reduced consumption of suction from condenser of steam-air mixture.1 cl, 1 dwg

Description

Technical field

The invention relates to the field of power engineering and can be used in thermal power plants (TPPs) equipped with condensation and cogeneration steam turbine plants.

State of the art

In the condensers of steam turbines of steam turbine plants of TPPs, the vapor-air mixture (PVA) is provided to create the vacuum required for the economical operation of the steam turbine. To carry out the suction of the PVA, water-jet ejectors are usually used, in which the pressure nozzle is connected to the water supply line from the circulating cooling system of the indicated condenser, moreover, a pump is installed on the specified line to create the water pressure required for the ejector to work, and the exhaust pipe of the ejector is open-connected to the drain water conduit circulating water. (Guidelines for testing, selecting performance, setting up and operating water-jet ejectors of condensing units of steam turbines of thermal power plants. RD 34.30.402-94, p. 24 [1]).

Such a suction circuit leads to significant costs associated with an increase in the flow rate of relatively expensive circulating water in excess of the required amount for cooling the turbine condenser and the cost of electricity to drive the specified pump.

A device for suctioning a steam-air mixture of a condenser of a steam turbine of a steam turbine installation, comprising a water-jet ejector, a pressure nozzle of which is connected to a water supply line from a circulating system of said condenser, is known (RU 2099608, F04F 5/54, 1997 - [2]) .

The device according to [2] provides water savings on the power of the ejector due to the introduction instead of an open circuit of a closed circuit of water circulation, passed through the specified ejector.

The disadvantages [2] include the need for the introduction of a bulky and metal-intensive prefabricated tank, a recirculation pump passed through the specified ejector of water and a heat exchanger for cooling water in the created new closed circulation loop.

Disclosure of invention

The problem to which the patented invention is directed is to reduce the cost of exhausting a steam-air mixture from a condenser, and the technical result is to eliminate the need for a closed circulation loop of water passed through the ejector.

The solution of this problem by achieving the specified technical result in relation to the patented invention is ensured by the fact that a device for sucking the steam-air mixture from the condenser of the steam turbine of the steam turbine installation, containing a water-jet ejector, the pressure nozzle of which is connected to the water supply line from the circulating system of the specified condenser,

according to the patented invention

it is additionally equipped with a steam-jet ejector, connected in parallel with the steam-air mixture sucked from the condenser, the pressure nozzle of which is connected to a line of one of the intermediate steam withdrawals of the specified turbine, its exhaust pipe - to the surface cooler inlet, included on the cooling side in the cut of the condensate path line between the low-pressure regenerative heaters specified steam turbine installation.

A causal relationship between the set of essential features of the patented invention and the achieved technical result is that the equipment of the patented device is connected in parallel via a steam-jet ejector sucked from the PVA condenser, the pressure nozzle of which is connected to the line of one of the intermediate steam withdrawals of the specified turbine, and its exhaust pipe - to the surface cooler included along the cooling side in the cut line of the condensate path between regenerative heating low pressure of the specified steam turbine unit, allows to reduce the cost of expensive circulating water for feeding a water-jet ejector in the warm season, when, on the one hand, due to the temperature increase, there is a special deficit in the specified water, and, on the other hand, the same reason its ejection properties worsen. At the same time, a steam-jet ejector does not require costs associated with an increase in the flow of circulating water used to cool the condenser, the heat of the selected steam of the turbine and the steam itself in the form of condensate are returned to the cycle of the working fluid of the steam turbine unit. In the cold season, when the flow rate of the circulating water for cooling the turbine condenser is significantly reduced, and the ejection capacity of water in the water-jet ejector increases, the PVA suction returns to the usual scheme of using a water-jet ejector without the need for a closed circulation loop of water passed through the ejector.

Legend

VE - water-jet ejector;

KN - condensate pump;

KP - steam condenser;

O - surface cooler;

PVA - vapor-air mixture;

PND - regenerative low-pressure heater;

PT - steam turbine;

PTU - steam turbine installation;

PE - steam jet ejector

TPP - thermal power station;

Brief Description of the Drawing

The drawing shows a patentable device and a diagram of its connection to the corresponding lines of the steam turbine plant TPP.

List of drawing items

10 - PT; 20 - KP; 21 - a pressure head conduit of the circulation cooling system KP PT; 22 - drain conduit of the circulation cooling system KP PT; 30 - line intermediate selection of steam PT; 31 - line for supplying steam to the pressure nozzle PE; 40 - line path of the return of condensate from the KP in the cycle of vocational schools; 50 - KN; 60 and 70 - regenerative PND; 80 - renewable energy; 81 - pressure nozzle VE; 82 - suction line of the vapor-air mixture from the steam space of the KP using VE; 83 - line for the removal of the PVA from the exhaust pipe; 90 - water supply line from the pressure pipe; 91 - a pump on the water supply line from the discharge conduit to the HE nozzle; 100 - PE; 101 - pressure nozzle; 102 - suction line of the vapor-air mixture from the steam space of the KP using PE; 103 - line for the removal of PVA from the exhaust pipe PE to the surface cooler; 200 - surface cooler of the steam-air mixture from PE; 201 - drainage line; 300, 400, 500, 600 - shutoff valves; 700 - jumper.

The implementation of the invention

The elements of a steam turbine installation (ПТУ), shown schematically in the drawing, include a steam turbine (ПТ) 10 with a steam condenser (KP) 20, the circulation cooling system of which is equipped with a pressure water supply pipe 21 and a drain water pipe 22, and an intermediate steam extraction line 30, as well as line 40 of the condensate return path from KP 20 to the vocational-technical cycle with the condensate pump (KN) 50 installed on it and regenerative low-pressure heaters (PND) 60 and 70.

The device according to the invention contains a water-jet ejector (VE) 80, the pressure nozzle 81 of which is connected to the water supply line 90 from the pressure pipe 21 of the KP 20 circulation cooling system, on which the pump 91 is installed to create the required water pressure. The suction nozzle of the ejector VE 80 is connected to the line 82 for exhausting the steam-air mixture from the steam space of the KP 20, and its exhaust pipe is connected to the line 83 of the exhaust pipe of the PVA to the drain conduit 22 of the circulating cooling system of the steam condenser KP 20.

The device according to the invention is additionally equipped with a steam-jet ejector (PE) 100, the pressure nozzle 101 of which is connected to the steam supply line 31 from the line 30 of one of the intermediate steam take-offs 10. The suction nozzle of the PE 100 ejector is connected to the line 102 for exhausting the vapor-air mixture from the steam space of KP 20 and its exhaust pipe — by the line of the PVA branch to the surface cooler (O) 200, included along the cooling side in the cut-out of the line 40 of the condensate return path between the HDPE 60 and the HDPE 70. A message with an atmosphere, an air vent (not shown), and in the lower part there is a drain line 201 for draining the condensate formed. The connection of the drainage line 201 to the KP 20 condenser is possible either directly through a water trap with a liquid column that resists atmospheric pressure, or through the steam sides of one or in series of two low-pressure PNDs using a standard drainage line (not shown in the drawing). Shut-off valves 300, 400, 500 and 600, respectively, are installed on pressure lines 90 and 31, as well as on lines 82 and 102 of the PVA suction from the steam space of the KP 20 of both ejectors. To ensure uniformity of the suction of the PVA from the KP 20 condenser during the autonomous operation of each of these ejectors between the lines 82 and 102 of the exhaust of the PVA from the steam space of the KP 20, a jumper 700 is provided.

The device according to the patented invention operates as follows.

In the cold season, at a temperature of circulating water no higher than 12 ÷ 15 ° С, the PVA is sucked out of the upper part of the steam compartment KP 20 using the water-jet ejector VE 80 according to the open circuit with the discharge of the sucked PVA via the discharge line 83 into the drainage conduit 22. valves 300 and 500 must be open, and shut-off valves 400 and 600 in the closed position. In the warm season, at temperatures above 12 ÷ 15 ° C, the water-jet ejector is switched off with the transfer of the PVA suction to the steam-jet ejector. For this, shut-off valves 400 and 600 are opened, followed by closing of shut-off valves 300 and 500. In hot weather, when the air temperature is above 25 ° С and the vacuum in the condenser worsens above the limit established by operational requirements, both ejectors can be switched on simultaneously.

Industrial applicability

The patented invention meets the condition of "industrial applicability". The essence of the technical solution is disclosed in the formula, description and drawing quite clearly, and the tools used are simple and affordable for industrial implementation in the field of heat power.

Claims (1)

A device for suctioning a steam-air mixture from a condenser of a steam turbine of a steam turbine installation, comprising a water-jet ejector, a pressure nozzle of which is connected to a water supply line from a circulating cooling system of said condenser, characterized in that it is additionally equipped with a steam-jet ejector, connected in parallel to a steam-air mixture sucked from the condenser, and a pressure head the nozzle of which is connected to the line of one of the intermediate steam withdrawals of the specified turbine, its exhaust pipe to the inlet surface cooler included along the cooling side in the cut line of the condensate path between the regenerative low-pressure heaters of the specified steam turbine installation.

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